5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Len Baker <len.baker@xxxxxxx> [ Upstream commit 746f1b0ac5bf6ecfb71674af210ae476aa714f46 ] As noted in the "Deprecated Interfaces, Language Features, Attributes, and Conventions" documentation [1], size calculations (especially multiplication) should not be performed in memory allocator (or similar) function arguments due to the risk of them overflowing. This could lead to values wrapping around and a smaller allocation being made than the caller was expecting. Using those allocations could lead to linear overflows of heap memory and other misbehaviors. So, use the array_size() helper to do the arithmetic instead of the argument "count * size" in the vzalloc() function. Also, take the opportunity to add a flexible array member of struct vm_memory_region_op to the vm_memory_region_batch structure. And then, change the code accordingly and use the struct_size() helper to do the arithmetic instead of the argument "size + size * count" in the kzalloc function. This code was detected with the help of Coccinelle and audited and fixed manually. [1] https://www.kernel.org/doc/html/latest/process/deprecated.html#open-coded-arithmetic-in-allocator-arguments Acked-by: Fei Li <fei1.li@xxxxxxxxx> Signed-off-by: Len Baker <len.baker@xxxxxxx> Signed-off-by: Gustavo A. R. Silva <gustavoars@xxxxxxxxxx> Stable-dep-of: 3d6586008f7b ("drivers/virt/acrn: fix PFNMAP PTE checks in acrn_vm_ram_map()") Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/virt/acrn/acrn_drv.h | 10 ++++++---- drivers/virt/acrn/mm.c | 9 ++++----- 2 files changed, 10 insertions(+), 9 deletions(-) diff --git a/drivers/virt/acrn/acrn_drv.h b/drivers/virt/acrn/acrn_drv.h index 1be54efa666cb..5663c17ad37c7 100644 --- a/drivers/virt/acrn/acrn_drv.h +++ b/drivers/virt/acrn/acrn_drv.h @@ -48,6 +48,7 @@ struct vm_memory_region_op { * @reserved: Reserved. * @regions_num: The number of vm_memory_region_op. * @regions_gpa: Physical address of a vm_memory_region_op array. + * @regions_op: Flexible array of vm_memory_region_op. * * HC_VM_SET_MEMORY_REGIONS uses this structure to manage EPT mappings of * multiple memory regions of a User VM. A &struct vm_memory_region_batch @@ -55,10 +56,11 @@ struct vm_memory_region_op { * ACRN Hypervisor. */ struct vm_memory_region_batch { - u16 vmid; - u16 reserved[3]; - u32 regions_num; - u64 regions_gpa; + u16 vmid; + u16 reserved[3]; + u32 regions_num; + u64 regions_gpa; + struct vm_memory_region_op regions_op[]; }; /** diff --git a/drivers/virt/acrn/mm.c b/drivers/virt/acrn/mm.c index 3b1b1e7a844b4..b4ad8d452e9a1 100644 --- a/drivers/virt/acrn/mm.c +++ b/drivers/virt/acrn/mm.c @@ -192,7 +192,7 @@ int acrn_vm_ram_map(struct acrn_vm *vm, struct acrn_vm_memmap *memmap) /* Get the page number of the map region */ nr_pages = memmap->len >> PAGE_SHIFT; - pages = vzalloc(nr_pages * sizeof(struct page *)); + pages = vzalloc(array_size(nr_pages, sizeof(*pages))); if (!pages) return -ENOMEM; @@ -244,16 +244,15 @@ int acrn_vm_ram_map(struct acrn_vm *vm, struct acrn_vm_memmap *memmap) } /* Prepare the vm_memory_region_batch */ - regions_info = kzalloc(sizeof(*regions_info) + - sizeof(*vm_region) * nr_regions, - GFP_KERNEL); + regions_info = kzalloc(struct_size(regions_info, regions_op, + nr_regions), GFP_KERNEL); if (!regions_info) { ret = -ENOMEM; goto unmap_kernel_map; } /* Fill each vm_memory_region_op */ - vm_region = (struct vm_memory_region_op *)(regions_info + 1); + vm_region = regions_info->regions_op; regions_info->vmid = vm->vmid; regions_info->regions_num = nr_regions; regions_info->regions_gpa = virt_to_phys(vm_region); -- 2.43.0
